RETURN VALVE FOR PIPELINE Russian patent published in 2001 - IPC

FIELD: pipeline appliances used in chemical, petroleum chemical and other branches of industry. SUBSTANCE: return valve is designed for cutting off pipeline in the case of breaking of pipeline or disturbances in operation of delivery pump, and has body 1, seat 2 and gate 4 adapted for cooperation with seat 2. Gate 4 is fixed in upper part of body 1 for rotation about horizontal axis 12 running through plane perpendicular to longitudinal axis 17 of body 1. Gate 4 has convex rear side 10 designed for creating lifting force acting in direction of "open" position. Return valve is equipped with at least one restricting member 21 arranged in body 1. When gate 4 is in its open position, it adheres to restricting member 21. Rear convex side of gate 4 has discharge part 9 provided with grooves 28 oriented perpendicular to axis 12 of rotation of gate 4. Return valve of such construction protects gas and hydraulic systems used in various types of pipeline systems from excessive pressure effects at hydraulic shocks and allows systems to be readily cut off in emergency cases. EFFECT: increased efficiency in cutting off pipeline systems, simplified construction and enhanced reliability in operation. 12 cl, 4 dwg